This invention relates to a braking and stopping system for movable or rollable containers, and is particularly directed to such a braking and locking system for containers adaptable for use in aircraft. In particular, the invention is directed to systems of this type, wherein the container is provided with a bottom plate which serves as a chassis, and is employed to support two pairs of associated braking spikes and locking levers.
Container systems internationally knows as "trolley systems", are well known, wherein brakes coupled to the wheels or rollers of the container are adapted to be actuated in response to the removal of a force. Such systems, which are known as "deadman" systems, are employed on heavy equipment, such as locomotives. This feature is also a necessity with respect to movable containers employed in aircraft, in order to avoid otherwise unavoidable accidents in operation. Such actions may arise, for example, due to the shifting attitude of an aircraft in which the container is being carried. Many variations of a further system, known as a "tie-down" system, are also known. In this system, a container is locked in position to the freight floor or to the loading floor of an aircraft, by means of a fixed mushroom-like anchor firmly attached to the floor, whereby a container trolley may be inhibited from moving in its rolling direction, as well as perpendicular to the rolling direction thereof. This arrangement ensures that the container remains firmly tied to the floor, especially of an aircraft, under conditions of sudden attitude changes of the aircraft. Such changes may occur, for example, when the aircraft drops in turbulent air. Anchors of the above type are frequently provided in the areas of the aircraft, wherein the containers are made ready, as well as in shunting areas displaced from the main passage. In the loading of a container into an aircraft, it must be moved in one direction to the position at which it will be locked for transport. When the container is unloaded, it must be unlocked, and then moved in the opposite direction in the aircraft. This does not present a problem with respect to the areas in which the containers are made ready, since in this case the containers always face with an end to a wall. At the so-called passage stations, however, the procedure of moving the containers is problematical, since the container must frequently be pulled from an anchor position at a time when the loading surface of the aircraft is inclined due to the attitude of a flight.
U.S. Pat. No. 3,710,895 discloses a container system including a combination of braking and locking systems, wherein the container has a bottom plate. The system includes locking levers which are pivotally mounted to cooperate with a mushroom-like anchor, as well as pairs of braking spikes adapted to engage the loading floor of the aircraft for braking the movement of the containers.
In the system of U.S. Pat. No. 3,710,895, the two locking levers, for stopping movement of the container in opposite directions, are adapted to be simultaneously controlled, so that release of the locking lever system permits the movement of a container in both of the rolling directions of the container. This is particularly hazardous in the storage compartment of the aircraft. For example, if an attempt is made to move the container from storage, it will tend to respond to the attitude of the aircraft. If an operator does not have sufficient strength to overcome the forces on the container resulting from the attitude of the aircraft, the container may strike a near compartment wall of the aircraft, or it may strike nearby containers.
In addition, in the arrangement of this system, danger also results when attempts are made to return the container to storage, and in this case it is also possible that the container may strike a wall of the aircraft.